1. Field of the Invention
The present invention relates to a signal converter for use in a recording or display device for suitably processing information signals representative of characters so that characters will be recorded or displayed with their size enlarged or reduced to a desired extent.
2. Description of the Prior Art
In general, with conventional impact type line printers used for data output from computers or the like it is impossible to change the size of characters to be recorded. Therefore, in order to change the size, many types in different sizes must be provided. In addition, the printing positions cannot be changed arbitrarily. Thus the conventional impact type line printers lack latitude and are insufficient in operation.
However, with the laser beam printers of the type wherein raster scanning is affected as well as multi-stylus electrostatic printers and CRT display devices, the size of characters to be recorded or displayed may be changed by suitably stepping down the frequencies of timing clocks for the main and auxiliary scannings thereby changing the read-out time from a character generator which is a character or symbol source. However, such devices have the disadvantage that all of the characters on one line must be changed of the same size so that it is impossible to change the size of only one or several desired characters on a line.
To solve this problem, there has been invented and demonstrated a system wherein, as disclosed in detail in Japanese Patent Laid-Open No. 104834/1975, a coded signal (which is interchangeably referred to as "a character code "or" an information signal" in this specification) of a character to be recorded or displayed in enlarged size includes a code for designating the enlargement of this character and addresses which addresses the enlarged character will occupy.
More particularly, assume that a character be enlarged both lengthwise and widthwise. In coding, two character codes representing the same character and each including an enlargement signal or code (which is also referred to as "an information signal" this specification) are arrayed in both lengthwise and widthwise so that the desired character may be enlarged at a position corresponding to the addresses included in the character codes. Therefore according to this system, the enlarged character extends over two lines so that in addition to recording or displaying characters in one line, enlargement of a desired character over two lines must be accomplished. As a result, a control circuit therefor is extremely complex in construction. Furthermore, the addition of the enlargement code to a character code results in the increase in bits used, and the increase in bits used in each character code results in an increase in the dimensions of the system. Conversely the dimensions of the system impose a limit to the number of character codes which permit the enlargement of characters in recording or displaying.